You probably want `CPXCALLBACKINFO_NODEDEPTH` not `CPX_CALLBACK_INFO_NODE_DEPTH`. Not a hard mistake to make!
---
### Author:  [@Matheus\_Diogenes\_And](https://discourse.julialang.org/u/Matheus_Diogenes_And)
#### Post date: [November 12, 2021, 6:42am UTC](https://discourse.julialang.org/t/get-branch-and-bound-node-depth-with-jump/71128/6 "2021-11-12T06:42:56Z")
Very thank you for your answer. The code is now executing, however, I think the results are not right. I used the commands as you suggested resulting in the function below:
```julia
function my_callback_function(cb_data::CPLEX.CallbackContext, context_id::Clong) # preliminary checkings
context_id != CPX_CALLBACKCONTEXT_CANDIDATE && return
ispoint_p = Ref{Cint}()
(CPXcallbackcandidateispoint(cb_data, ispoint_p) != 0 || ispoint_p[] == 0) && return # getting depth
depth = Ref{Clong}()
CPXcallbackgetinfolong(cb_data, CPXCALLBACKINFO_NODEDEPTH, depth)
println(depth[])
end
```
And I getting really strange results, specifically very big numbers, such as 52465968, 140258102699840,…
I think that the conditions ` (CPXcallbackcandidateispoint(cb_data, ispoint_p) != 0 || ispoint_p[] == 0)` are not enough. Which is strange, since according to the [documentation](https://www.ibm.com/docs/en/icos/20.1.0?topic=manual-cpxcallbackinfo) this is a valid condition. If anyone has ever faced such a thing I would like to hear something.
Thank you.
UPDATE 1: Fixing code typing error.
---
### Author:  [@jd-foster](https://discourse.julialang.org/u/jd-foster)
#### Post date: [November 12, 2021, 12:16pm UTC](https://discourse.julialang.org/t/get-branch-and-bound-node-depth-with-jump/71128/7 "2021-11-12T12:16:59Z")
> [@Matheus\_Diogenes\_And](#):
>
> `(CPXcallbackcandidateispoint(cb_data, ispoint_p) != 0 || ispoint_p[]) == 0`
Quick thought: are you sure the last bracket is where you want it? If this is a Bool comparison, I would use `false` over `0`, or do you want `ispoint_p[] == 0)`?
---
### Author:  [@Matheus\_Diogenes\_And](https://discourse.julialang.org/u/Matheus_Diogenes_And)
#### Post date: [November 12, 2021, 4:33pm UTC](https://discourse.julialang.org/t/get-branch-and-bound-node-depth-with-jump/71128/8 "2021-11-12T16:33:29Z")
Now it is, it was a typing error, even with the bracket at the right place, the error still persists.
---
### Author:  [@odow](https://discourse.julialang.org/u/odow)
#### Post date: [November 13, 2021, 9:50pm UTC](https://discourse.julialang.org/t/get-branch-and-bound-node-depth-with-jump/71128/9 "2021-11-13T21:50:00Z")
On some platforms `Clong != CPXLONG`. Try:
```nohighlight
function my_callback_function(cb_data::CPLEX.CallbackContext, context_id::Clong)
if context_id != CPX_CALLBACKCONTEXT_CANDIDATE
return
end
ispoint_p = Ref{Cint}()
ret = CPXcallbackcandidateispoint(cb_data, ispoint_p)
if ret != 0 || ispoint_p[] == 0
return
end
depth = Ref{CPXLONG}()
ret = CPXcallbackgetinfolong(cb_data, CPXCALLBACKINFO_NODEDEPTH, depth)
@assert ret == 0
println(depth[])
end
```
---
### Author:  [@Matheus\_Diogenes\_And](https://discourse.julialang.org/u/Matheus_Diogenes_And)
#### Post date: [November 15, 2021, 4:12am UTC](https://discourse.julialang.org/t/get-branch-and-bound-node-depth-with-jump/71128/10 "2021-11-15T04:12:58Z")
Thanks for the answer, but the problem still persists. Follows the complete code so you can check the behavior on your own machine.
```julia
using JuMP, CPLEX, Test
model = direct_model(CPLEX.Optimizer())
set_silent(model)
MOI.set(model, MOI.NumberOfThreads(), 1)
@variable(model, 0 <= x <= 2.5, Int)
@variable(model, 0 <= y <= 2.5, Int)
@objective(model, Max, y)
function my_callback_function(cb_data::CPLEX.CallbackContext, context_id::Clong)
#function my_callback_function(cb_data::CPLEX.CallbackContext, context_id::CPXLONG)
# preliminary checkings
context_id != CPX_CALLBACKCONTEXT_CANDIDATE && return
# ispoint_p = Ref{Cint}()
ispoint_p = Ref{CPXINT}()
(CPXcallbackcandidateispoint(cb_data, ispoint_p) != 0 || ispoint_p[] == 0) && return
# getting depth
# depth = Ref{Clong}()
depth = Ref{CPXLONG}()
CPXcallbackgetinfolong(cb_data, CPXCALLBACKINFO_NODEDEPTH, depth)
println(depth[])
end
MOI.set(model, CPLEX.CallbackFunction(), my_callback_function)
optimize!(model)
```
Thanks for the consideration.
---
### Author:  [@odow](https://discourse.julialang.org/u/odow)
#### Post date: [November 15, 2021, 6:09am UTC](https://discourse.julialang.org/t/get-branch-and-bound-node-depth-with-jump/71128/11 "2021-11-15T06:09:12Z")
> CPXcallbackgetinfolong(cb\_data, CPXCALLBACKINFO\_NODEDEPTH, depth)
You need to check the return code to see if the call succeeded. I’m guessing it didn’t. Probably because there was no node and the problem was solved at the root node via heuristics?
More generally, you need to read the CPLEX documentation in more detail: [IBM Documentation](https://www.ibm.com/docs/en/icos/20.1.0?topic=manual-cpxcallbackinfo)
You say you only want to add cuts at the root, but `CPX_CALLBACKCONTEXT_CANDIDATE` indicates that you have a valid integer solution. Perhaps you want `CPXCALLBACKINFO_NODECOUNT` or `CPXCALLBACKINFO_NODEUID`? instead?
---
### Author:  [@Matheus\_Diogenes\_And](https://discourse.julialang.org/u/Matheus_Diogenes_And)
#### Post date: [November 15, 2021, 9:49am UTC](https://discourse.julialang.org/t/get-branch-and-bound-node-depth-with-jump/71128/12 "2021-11-15T09:49:59Z")
Thank you, now it seems to be working.
```julia
using JuMP, CPLEX
model = direct_model(CPLEX.Optimizer())
set_silent(model)
MOI.set(model, MOI.NumberOfThreads(), 1)
@variable(model, 0 <= x <= 2.5, Int)
@variable(model, 0 <= y <= 2.5, Int)
@objective(model, Max, y)
function my_callback_function(cb_data::CPLEX.CallbackContext, context_id::Clong)
ispoint_p = Ref{CPXINT}()
(CPXcallbackcandidateispoint(cb_data, ispoint_p) != 0 || ispoint_p[] == 0) && return
n = Ref{CPXLONG}()
CPXcallbackgetinfolong(cb_data, CPXCALLBACKINFO_NODECOUNT, n)
println(n[])
end
MOI.set(model, CPLEX.CallbackFunction(), my_callback_function)
optimize!(model)
```
I just question myself why the above program is printing 0 twice.
---
### Author:  [@odow](https://discourse.julialang.org/u/odow)
#### Post date: [November 15, 2021, 7:09pm UTC](https://discourse.julialang.org/t/get-branch-and-bound-node-depth-with-jump/71128/13 "2021-11-15T19:09:36Z")
> [@Matheus\_Diogenes\_And](#):
>
> I just question myself why the above program is printing 0 twice.
Because your callback gets called multiple times at the root node.
Additionally, you are still not checking the return code of `CPXcallbackgetinfolong` for success.